It is the purpose of this project to define a skin bioassay for carcinogens which is more rapid and more sensitive, hence, less expensive than conventional skin bioassay in mice. The new hamster skin bioassay so defined will have applicability in studies of pesticides, herbicides, cosmetics, metallurgic dusts and powders, etc., as well as in studies on tobacco smoke condensate. Based on the fact that several of our 27 BIO inbred Syrian golden hamster strains are highly susceptible to subcutaneously injected or gavaged polycyclic hydrocarbons and that hamsters are considerably more resistant than mice to the toxic effects of nicotine, the proposed investigation will test the hypothesis that hamsters constitute an important - albeit neglected - species for bioassay of the carcinogenicity of cigarette smoke condensate, as determined by application of such condensates to the skin. We will determine the effect of sex and strain on response to skin application of cigarette smoke condensates derived from kentucky reference cigarettes, as compared with Benzo(a)pyrene (BaP) applied in concentrations presumably close to those naturally occurring in the condensates. Inbred strains to be compared will include (but not be limited to) BIO 15.16 and BIO 87.20, shown by our inhalation studies to be sensitive and resistant, respectively, to the induction of laryngeal cancer by lifetime exposure to inhaled tobacco smoke.